Automaton

The term automaton evokes the image of a mechanical toy or a soulless organism like a golem, but in computer science it has a very precise meaning. It refers to all machines whose output behaviour is not a direct consequence of the current input, but of some past history of its inputs. They are characterised as having an internal state which is a repository of this past experience. The inner state of an automaton is private to the automaton, and is not available to an external observer.

An automaton is a machine or computing device that performs a function according to a predetermined set of coded instructions, especially one capable of a range of programmed responses to different circumstances.